PRECIPITATION SYSTEM AND PRECIPITATION METHOD

A precipitation system for precipitating the target component is provided. The precipitation system includes: a reverse osmosis module; a precipitation device; a membrane separation device that includes a semipermeable membrane module including a first chamber and a second chamber separated by a semipermeable membrane, and that makes the feed solution after precipitation of the target component in the precipitation device flow to each of the first chamber and the second chamber and pressurizes the feed solution in the first chamber to transfer water into the second chamber via the semipermeable membrane and thereby concentrate the feed solution in the first chamber and dilute the feed solution in the second chamber; first return means for returning the feed solution concentrated in the membrane separation device to the precipitation device; and second return means for returning the feed solution diluted in the membrane separation device to the reverse osmosis module.